3		7		6			5
		4		1
6
7	3
						3	1
							6
			7		6
4			8		1		7

Difficulty: Very easy (0)

			2		6		5
					1
				6	8
					2	4
	5	2
		4	7
		1
3		5		1

Difficulty: Very easy (0)

				7	6
						8
8				2
			5		7	4
	1	7		8
			8				6
	7
		1	6

Difficulty: Easy (0)

				2
				4	8
				5			3
	5		4	8
			3	1		5
6			2
		4	6
			1

Difficulty: Very easy (0)